Are you on Windows or Mac? What file are you trying to transfer? You need to have last year’s file ending in .tax2023 to transfer on your computer.
Here's an idea. Do you still have 2023 installed? Try opening 2023 program and see if you can get your 2023 return to show up in it. Go to FILE - OPEN. Then save it again with a name and place you can find. Go to File - Save As. Then start a new 2024 return and transfer from the 2023 file.
Here's how to transfer last year's return to Windows Desktop program
https://ttlc.intuit.com/community/entering-importing/help/transfer-last-year-s-return-to-turbotax-fo...
How to transfer into Turbo Tax for Mac
https://ttlc.intuit.com/community/tax-data-file/help/how-do-i-transfer-last-year-s-return-into-the-t...
